Modern injection systems for internal combustion engines in motor vehicles generally have a high-pressure fuel circuit via which the injection valves of the internal combustion engine are supplied with fuel, there being disposed in the high-pressure fuel circuit a volume control valve (VCV) which lets through a particular volume flow of fuel depending on how it is operated. The volume control valve is customarily operated via an output stage by a pulse width modulated voltage signal whose duty factor is varied as a function of the desired degree of opening of the volume control valve. To control the operation of the volume control valve, the electric current flowing through the volume control valve and representing the degree of opening of the volume control valve is measured at the end of each period of the pulse width modulated control signal. Depending on the thus determined actual value of the current flowing through the volume control valve or rather of the corresponding degree of opening of the volume control valve, the duty factor of the pulse width modulated control signal is varied as part of a control process in order to set the desired degree of opening of the volume control valve.
The disadvantage of this known regulating method for operating the volume control valve is the dead time resulting from the fact that the control variable is only varied from one period to the next, but not within a period.
Another disadvantage of the known regulating method described above is the over- or undershooting of the volume control valve about the predefined setpoint value.